1. Field of the Invention
The present invention is directed generally to fiber optic communication systems and more specifically to optical coupling systems for wavelength-individual through-connection between wavelength-division multiplex (WDM) input and output fibers given simultaneously possible wavelength conversion.
2. Description of the Related Art
WDM coupling system having wavelength demultiplexers on the input side, wavelength multiplexers on the output side, and wavelength converters for wavelength conversion onto the respectively outgoing wavelength, as well as a space coupling arrangement lying therebetween, are known, for example, from ntz 46 (1993)1, pages 16-21 (see FIG. 13 and FIG. 14 therein). A WDM coupling system having the same structure is also known from Conf. Proc. ICC '93, pages 1300-1307. Such a WDM coupling system includes: wavelength demultiplexers at the input side that respectively divide the incoming optical signal on the associated input fiber according to wavelengths; a subsequent space coupling arrangement; subsequent variable wavelength converters that convert the respectively incoming wavelength onto the respectively outgoing wavelength; and wavelength multiplexers at the output side that combine the wavelengths supplied to them.